Imidazolyl phosphates and phosphorothioates



United States Patent 3,519,639 IMIDAZOLYL PHOSPHATES AND PHOSPHOROTHIOATES Paul B. Budde and Henry Tolkmith, Midland, MiClL, as-

signors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Continuation-impart of application Ser. No. 604,177, Dec. 23, 1966. This application May 24, 1968, Ser. No. 731,745

Int. Cl. C07d 49/36 U.S. Cl. 260-309 Claims ABSTRACT OF THE DISCLOSURE This is a continuation-in-part of the application which is identified as Ser. No. 604,177, filed Dec. 23, 1966 now abandoned.

The present invention is concerned with imidazolyl and diimidazolyl phosphates and phosphorothioates of the formulas and In the above and succeeding formulas in the present specification and claims, each X and X represents oxygen or sulfur, R represents hydrogen or loweralkyl; each G represents a radical of the formula and G represents G, loweralkylamino, or aryl of the formula n i R wherein each R represents bromo, chloro, cyano, nitro, or loweralkoxy; each R" represents bromo, chloro, or loweralkyl and n represents an integer 0, 1, or 2. In the present specification and claims, the terms loweralkyl and loweralkoxy wherever employed herein designates alkyl and alkoxy, radicals, respectively, whereof the alkyl portion is an alkyl radical being from 1 to 2, to 3,

3,519,639 Patented July 7, 1970 ice and up to and including 4 carbon atoms and 1 and 2 and 3 and 4 carbon atoms. The term loweralkylamino denotes amino groups in which the alkyl portion is similarly of 1 to 4 carbon atoms. Representative loweralkylamino groups include methylamino, dimethylamino, ethylamino, diethylamino, n-propylamino, di-n-propylamino, isopropylamino, diisopropylamino, methylethylamino, methylisopropylamino, ethyl-n-propylamino, isobutylamino, and so forth.

The products of the present invention as above defined are typically viscous liquids or crystalline solids at room temperature. They are of low to moderate solubility in various organic solvents. They are useful as agents to control the growth of bacterial and fungal organisms such as the causative agents of various plant diseases, for example, apple scab, potato late blight, and the like. Representative compounds of the present invention include:

(2-chloro-4-n-butyl-phenoxy) bis (2-methy1imidazol-1-yl)- phosphine oxide,

(2-chloro-4-t-butyl-phenoxy bis Z-ethyl-imidazoll-yl phosphine sulfide,

(2-chloro-4-t-butyl-phenoxy)diimidazol-l-ylphosphine oxide,

( 4-chlorophenoxy) (4-chlorophenyl imidazoll-ylphosphine oxide,

( 4-chlorophenoxy) (dimethylarnino)imidazoll-ylphosphine oxide,

(2,4,5-trichlorophenoxy) (dimethylamino)imidazol-lylphosphine oxide,

( 3-bromo-5-methoxyphenoxy) (methylisopropylamino) (Z-ethylimidazol-1-y1)phosphine sulfide,

(2-chloro-4-nitrophenoxy) (methylamino)imidazol-1- ylphosphine oxide,

(2-bromo-4-cyanophenoxy) (diethylamino)imidazol-lylphosphine oxide,

(2,6-dimethyl-4-cyanophenoxy)bis(2-ethylimidazol-1- yl)phosphine sulfide,

( 2-chflioro-4-methylphenylthio diimidazoll-ylphosphine sul de,

( 4cyanophenylthio) (dimethylamino) (Z-methylimidazol-l-yl) phosphine oxide,

(4-bromophenylthio) (4-bromophenyl)imidazol-l-ylphosphine sulfide,

(4-isopropoxyphenoxy) (isop ropylamino) (Z-n-butylimidazol-l-yl)phosphine oxide,

(2,4,S-trichlorophenoxy)(n-butylamino)imidazol-1- ylphosphine sulfide, and

(2-chloro-4-t-butyl-phenylthio) (ethylamino imidazoll-ylphosphine oxide.

The products of the present invention are prepared by introduction of one or more of the requisite imidazolyl LN iQl moieties into a phosphorus containing compound. The introduction is achieved by reaction of an imidazole compound of the formula with an appropriate phosphoms containing reactant.

The identity of the latter reactant is dependent upon the number of imidazolyl moieties to be introduced.

3 Where a product of Formula I is desired, the phosphorus containing reactant employed is of the formula:

i G-I -Clz and where a product of Formula II is desired, the phosphorus containing reactant is of the formula:

l ci Regardless of the identity of the phosphorus containing reactant, the reaction of it with the imidazole reactant is carried out in the presence of a hydrogen chloride acceptor, such as a tertiary amine or an excess amount of the imidazole reactant. Furthermore, the reaction of imidazole reactant and phosphorus containing reactant is conveniently carried out in the presence of an inert liquid reaction medium. Suitable such media include aromatic hydrocarbons, such as benzene and toluene; and ethers, such as 1,2-dimethoxyethane, diethyl ether, and tetrahydrofuran. The reaction goes forward under temperatures of a wide range, such as from to 100 C., but is preferably carried out at temperatures of from 20 to 60 C. The reaction results in the preparation of the desired product of either Formula I or II and of hydrogen chloride byproduct, which byproduct appears in the reaction medium as the reaction product of the hydrogen chloride acceptor-the hydrogen chloride addition salt when a tertiary amine or excess imidazole reactant is employed as the acceptor. The reaction goes forward when employing the reactants and hydrogen chloride acceptor in any amounts; however, the reactants are consumed in amounts representing equimolecular proportions and the employment of such amounts is preferred.

In carrying out the reaction, the reactants and hydrogen chloride acceptor are contacted with one another. The contacting is generally carried out by adding one reactant to the other reactant in a reaction medium containing the other reactant and the hydrogen chloride acceptor. Generally, the reaction goes to completion with the completion of the contacting of the reactants; however, it is sometimes preferred to permit the reaction mixture to stand for a period of time to assure completion of the reaction. Following any such period, the product is conventionally separated and recovered from the reaction mixture. The reaction mixture can be filtered to separate the byproduct hydrochloride salt. The solvent can then be removed from the filtrate by evaporation under subatmospheric pressure to leave the product as a residue. If desired, the product can be purified in conventional procedures; however, it is not necessary that such purification be carried out.

In an alternate method, the products of Formula II wherein G represents loweralkylamino are prepared by a modification of the foregoing method. In this modification, a single imidazolyl moiety is introduced into a precursor of the formula mula H wherein G represents loweralkylamino. Good results are obtained when employing, in the first reaction of this method, equimolecular proportions of imidazole compound, the phosphorus containing compound, and hydrogen chloride acceptor. In the second reaction, good results are obtained when employing equimolecular proportions of the previously obtained compound:

X G l .2 l i 01 the loweralkylamine reactant, and a hydrogen chloride acceptor. An excess amount of the loweralkylamine reactant can be employed. In other respects than the preferred amounts to be employed, the reactions are carried out in accordance with the general method of which this is an alternate.

The following examples illustrate the present embodiment of the invention and will enable those skilled in the art to practice the same.

EXAMPLE 1.-(2 CHLORO 4 t BUTYL PHE- NOXY) (DIMETHYLAMINO) IMIDAZOL 1 YLPHOSPHINE SULFIDE O (2 chloro 4 t butyl phenyl)phosphorodichloridothioate (227.5 grams; 0.716 mole) is mixed with 2 liters of benzene. The mixture is stirred and imidazole (97.6 grams; 1.432 moles) added portionwise over a period of 5 hours. The reaction mixture during the addition is maintained at a temperature of about 25 30 C. Following the 5-hour period, the reaction mixture is held at room temperature, with stirring, for an additional period of twelve hours. At the end of this time, the reaction mixture is filtered to separate imidazole hydrochloride byproduct, which is then washed with 500 milliliters of benzene, and the filtrate and Wash combined. The combined filtrate and wash (representing about 0.716 mole of O- (2-chloro-4-t-butyl-phenyl imidazoll -ylphosphorochloridothioate) is cooled with stirring to 0-5 C. and dimethylamine (68.2 grams; 1.5 moles) added over a 5-hour period. The reaction mixture is maintained during the addition at the 0-5 C. temperature range. After the addition, the reaction mixture is held at the same temperature for an additional 8 hours, with stirring. The reaction mixture is then filtered to separate the dimethylamine hydrochloride byproduct and the benzene removed by evaporation under subatmospheric pressure to obtain the desired (2-chloro-4-t-butyl-phenoxy) (dimethylamino) imidazol-l-ylphosphine sulfide product. (2-chloro-4-t-butyl-phenoxy) (dimethylamino)imidazol-l-ylphosphine sulfide has a molecular weight of 347.8.

EXAMPLE 2. (4-BROMOPHENOXY) (DIMETH- YLAMINO)IMIDAZOL 1 YLPHOSPHINE SUL- FIDE O-(4 bromophenyl)phosphorodichloridothioate (123 grams; 0.4 mole) is mixed with 500 milliliters of benzene. Thereafter dimethylamine (36 grams; 0.8 mole) is added portionwise over a period of 4 hours, the addition being carried out with the reaction mixture at a temperature of 30-32 C. After, the completion of the addition, the reaction mixture is held with stirring at room temperature for about 15 hours. The reaction mixture is then filtered to remove dimethylamine hydrochloride byproduct which is subsequently washed with milliliters of benzene. The filtrate and wash are combined and imidazole (56.0 grams; 0.8 mole) added portionwise to the combined filtrate and wash. The addition is carried out at room temperature over a 3 hour period. After this addition, the reaction mixture is stirred at room temperature for an additional 12 hours. Insoluble imidazole hydrochloride byproduct is removed by filtration and washed. The filtrate and Wash are combined and benzene removed by evaporation under subatmospheric pressure to obtain the desired (4-bromophenoxy) (dimethylamino)imidazol-l-ylphosphine sulfide product as a residue. The product residue is mixed with 500 milliliters of carbon tetrachloride, the mixture filtered, and the carbon tetrachloride removed by evaporation under subatmospheric pressure to obtain the product. (4-brom0phenoxy) (dimethylamino)imidazol 1 ylphosphine sulfide has a molecular weight of 336.3.

EXAMPLE 3.--(2-CHLORO-4-t-BUTYL-PHENOXY) METHYLAMINO(2 ETHYLIMIDAZOL l-YL) PHOSPHINE SULFIDE -(2-chloro-4-t butyl phenyl)phosphorodichloridothioate (227.5 grams; 0.716 mole) is dissolved in 1.2 liters of benzene. The mixture is thereafter stirred and cooled and maintained at a temperature ranging from 0 to C. While maintaining the reaction mixture at this temperature, monomethylamine (49.0 grams; 1.58 moles) is added over a two hour period while continuing with stirring. Following the two hour period, the reaction mixture is held at from 0 C. to 5 C., with stirring, for an additional period of sixteen hours. At the end of this time, the reaction mixture is filtered to separate the insoluble methylamine hydrochloride which is then washed with 500 milliliters of benzene. The filtrate and wash are combined and concentrated by vacuum evaporation. The concentrate is then dissolved in one liter of n-hexane, the resulting mixture is filtered, and the filtrate is evaporated to give O-(2-chlor0-4-tbutylphenyl) -N-methylphosphoramidochloridothioate.

To a solution of 98.5 grams (0.316 mole) of the thus .obtained O-(2-chloro-4-t-butylphenyl)-N-methylphosphoramidochloridothioate in 200 milliliters of 1,2- dimethoxyethane is added, with stirring, a solution of 31 grams (0.316 mole) of 2-ethylimidazole, 56 milliliters (0.4 mole) of triethylamine and 200 milliliters of 1,2-dimeth0xyethane in a dropwise fashion while maintaining the entire reaction mixture at room temperature. After the addition is complete, the reaction mixture is stirred at about 85 C. for four hours. Thereafter, 500 milliliters of 1,2-dirnethoxyethane are added to the reaction mixture. The insoluble triethylamine hydrochloride is removed by filtration. The filtrate is concentrated and the concentrate purified through three crystallizations from a benzenezcyclohexane (1:1) mixture to give the desired (Z-chloro-4-t-butyl-phenoxy) methylamino(Z-ethylimidazol 1 yl)phosphine sulfide product melting at from 110 to 111 C.

EXAMPLE 4.(2,4 DICHLOROPHENOXY)ISO- PROPYLAMINOIMIDAZOL 1 YLPHOSPHINE SULFIDE A solution of 271 grams (0.85 mole) of O-(2,4-dichlorophenyl)phosphorodichloridothioate is dispersed in 1500 milliliters of benzene and the resultant solution is stirred at a temperature of from 0 C. to 5 C. Over a three hour period 150 milliliters (1.75 moles) of isopropylamine is added dropwise to the stirred solution. is stirred for 16 hours while maintaining the temperature at from 0 C. to 5 C. and thereafter the reaction mixture is refluxed for 1 hour. 500 milliliters of benzene are added to the mixture, the insoluble isopropylamine hydrochloride is filtered and removed, and the remaining filtrate is concentratedby evaporation to give 0-(2, 4-dichlorophenyl)-N isopropylphosphoramidochloridothioate as a crude residue which is recrystallized twice from n-hexane. This product has a melting point of 51 C.

A solution of 64 grams (0.2 mole) of O-(2,4-dichlorophenyl) --N isopropylphosphoramidochloridothioate in 200 milliliters of 1,2-dimeth0xyethane is stirred and to it is added dropwise over a 2 hour period at room temperature a solution of 14 grams (0.2 mole) of imidazole, 35 milliliters (0.25 mole) of triethylamine, and 100 milliliters of 1,2-dimethoxyethane. After the addition has been completed, the reaction mixture is stirred at from 55 C. to 60 C. for 17 hours. Thereafter, an additional 250 milliliters of 1,2-dimethoxyethane is added to the reaction mixture, the insoluble triethylamine hydrochloride is filtered and removed, and the filtrate is concentrated. The concentrate is crystallized in cyclohexane to give the desired product (2,4- dichlorophenoxy)isopropylaminoimidazol l-ylphosphine sulfide product melting at from 92 to 99 C.

Other representative products prepared in accordance with the foregoing teachings and examples, are set forth in the following table. The symbol M.P. is employed as an abbreviation of the term melting point, and the symbol m. wt. as an abbreviation of the term molecular weight. The identity of the products is confirmed by elemental analysis.

From (2,4,5-trichlorophenoxy)dichlorophosphine sul fide and imidazole, (2,4,5-trichlorophenoxy)diimidazoll-ylphosphine sulfide, a viscous liquid having a in. wt. of 39516.

From (2,4,5-trichlorophenoxy)dichlorophosphine sulfide, imidazole, and dirnethylamine, (2,4,5-trichlorophenoxy) (dimethylamino)imidazol-l-ylphosphine sulfide, M.P. 9495 C.

From (p-bromophenoxy)dichlorophosphine oxide and 2-ethylimidazole, (p-bromophenoxy)bis(2-ethy1imidazol- 1-yl)phosphine oxide, M. Wt. 409.2.

From (2 chloro-4-t-butyl phenoxy)dichlorophosphine oxide, imidazole, and dimethylamine, (2-chloro-4-t-butyl phenoxy) (dirnethylamino)imidazol-l-ylphosphine oxide, a viscous liquid having a M. Wt. of 331.8.

From (m-nitrophenylthio)dichlorophosphine sulfide and imidazole, (m-nitrophenylthio)diimidazol-l-ylphosphine sulfide, M. Wt. 351.3.

From (2-chloro-4-t-butyl-phenylthio)dichlorophosphine sulfide and imidazole, (2-chloro-4-t-butyl-phenoxy)diimidazol-l-ylphosphine sulfide, M. Wt. 364.8.

From (p-isopropoxyphenoxy)dichlorophosphine oxide, imidazole, and 2-is0butylimidazole, (p-isopropoxyphenoxy)imidazol-l-yl-(2-isobutylimidazol-l-yl)phosphine 0X- ide, M. Wt. 388.5.

From (m-nitrophenoxy)dichlorophosphine sulfide 2- methylimidazole, noxy) (di-n-propylamino) (2 methylimidazol-l yl)phosphine sulfide, M. Wt. 382.4.

From (2,4,5-trichlorophenoxy)dichlorophosphine sulfide, imidazole, an N-n-butylmethylamine, (2,4,5-trichlorophenylthio) (N n butylmethylamino)imidazol-lylphosphine sulfide, a viscous liquid.

From (2,4,5-trichlorophenoxy)dichlorophosphine sulfide, imidazole, and diethylamine, (2,4,5-trichlorophenoxy)(diethylamino)imidazole 1 ylphosphine sulfide, M.P. 36-42 C.

From (2 chloro-4-t-butyl-phenoxy)dichlorophosphine oxide and Z-methylimidazol, (2-chloro-4-t-butyl-phenoxy)bis(2-methylimidazol-1-yl)phosphine oxide, M. Wt. 392.8.

From p chlorophenyl(p-chlorophenylthio)chlorophosphine sulfide, and 2-ethylimidazole, p-chlorophenyl-(pchlorophenylthio) (2-ethylimidazol-1-yl)phosphine sulfide, M. Wt. 414.4.

From (2 chloro-4-t-butyl-phenoxy)dichlorophosphine sulfide, imidazole, and diethylamine, (2-chloro-4-t-butylphenoxy) (diethylamino)imidazol-l-ylphosphine sulfide, a viscous liquid having a M. Wt. of 375.8.

From (2 chloro 4-t-butyl-phenoxy)3,5 dimethoxyphenylchlorophosphine sulfide and imidazole, (2-chloro-4- t butylphenoxy)3,S-dimethyloxyphenylimidazol 1 ylphosphine sulfide, M. Wt. 350.9.

From (2 chloro-4-t-butyl-phenoxy)dichlorophosphine oxide, imidazole, and diethylamine, (2-chloro-4-t-butylphenoxy)(diethylamino)imidazol-l-ylphosphine oxide a viscous liquid having a M. Wt. of 359.8.

From (2,4-dichlorophenoxy)dichlorophosphine sulfide and Z-methylimidazole, (2,4 dichlor0phenoxy)bis-(2- methylimidazol-l-yl)phosphine sulfide, M. Wt. 387.2.

From (p-nitrophenoxy)dichlorophosphine sulfide and 2- methylimidazole, (p-nitrophenoxy) bis (2-methylimidazol- 1-yl)phosphine sulfide, M. Wt. 363.4.

and di-n-propylamine, (m-nitrophe-' From (2 chloro-4-t-butyl-phenoxy)dichlorophosphine oxide, and imidazole, (2-chloro-4-t-butyl-phenoxy)-diimidazol-l-ylphosphine oxide, M. Wt. 364.8.

From (2,4 dichlorophenyl)phosphoroclichloridothioate and isopropylarnine and Z-methylirnidazole, (2,4- dichlorophenoxy)isopropylamino(2 methylimidazol 1- yl)-phosphine sulfide, M.P. 91 to 96 C.

From (2 chloro-4-t-butyl-phenoxy)dichlorophosphine sulfide and Z-methylimidazole, (2-chloro-4-t-butyl-phenoxy)-bis(2-methylimidaZole-1-yl)phosphine sulfide, M. Wt. 408.8.

From 0 (2,4 dichlorophenyl)phosphorodichloridothioate and isopropylamine and 2-ethylimidazole, (2,4- dichlorophenoxy)isopropylamino(2-ethylimidazol 1 yl) phosphine sulfide, MP. 98 102 C.

From 0 (2-chloro-4-t-butyl-phenyl)phosphorodichloridothioate and isopropylamine and 2-methylimidazole, (2 chloro-4-t-butyl-phenoxy)isopropylamino(2 methylimidazol-1-yl)phosphine sulfide, a thick gum.

From 0 (2-chloro-4-t-butyl-phenyl)phosphorodichloridothioate and isopropylamine and 2-ethylimidazole, (2- chloro-4-t-butyl-phenoxy)isopropylamino(2 ethylimidazol-l-yl)phosphine sulfide, M.P. 93-95 C.

From 0 (2 chloro-4-t-butyl-phenyl)dichloridophosphonate and isopropylamine and Z-ethylimidazole, (2- chloro-4-t-butyl-phenoxy isopropylamino 2 ethylimidazol-1-yl)phosphine oxide, M.P. 86-91 C.

From 0 (2-chlorophenyl)phosphorodichloridothioate and n-propylamine and 2-methylimidazole, (2-chlorophenoxy)-n-propylamino(Z-rnethylimidazol 1 yl)phosphine sulfide, M. Wt. 331.7.

From 0 (3-bromo-5-meth0xyphenyl)dichloridophosphonate and isopropylamine and 2-ethylimidazole, (3- bromo-S-methoxyphenoxy)isopropylamino(2 ethylimidazol-1-yl)phosphine oxide, M. Wt. 408.2.

As noted hereinabove, the products of the present invention are useful as agents to control the growth of bacterial and fungal organisms. In this capacity, they can be employed to control such organisms as powdery mildew, potato late blight, fire blight, rice blast, Triclzophyton mentagrophytes, apple scab, bean mildew, potato scab, tomato early blight, Cercosphora beticola, Staphylococcus aureus, Asperg'illus terreus, Candida pelliculosa, Rhizopus nigricans, and Bacillus subtillis.

When a product of the present invention is employed for its bactericidal and fungicidal properties, the unmodified product can be utilized. However, the present invention also encompasses the utilization of the product together with an adjuvant. For example the product can be dispersed on a finely divided solid and the resulting preparation employed as a dust. Also, a product of the present invention, or a composition comprising a product of the present invention and a finely divided solid, can be dispersed in water with the aid of a wetting agent and the resulting aqueous suspension employed as a spray. In other procedures, a product according to the present invention can be employed as the constituent of organic liquid compositions, oil-in-water or water-in-oil emulsions, or water dispersions, with or without the addition of a wetting, dispersing, or emulsifying agent. Good results are obtained when employing compositions containing bactericidal and fungicidal amounts of one or more of the active compounds. Generally, compositions are employed which contain from to 10,000 parts of one or more of the active compounds per million parts by weight.

In representative operations, a stand of cucumber plants sprayed with an aqueous composition containing as sole fungicidal agent 150 parts of (2,4,5-trichlorophenoxy) (dimethylamino)imidazol-l-yl-phosphine sulfide per million parts by weight of total composition are completely protected against a subsequent challenge with powdery mildew. Another stand of cucumber plants left untreated to serve as checks develop a severe infestation of powdery mildew when similarly challenged.

In other representative operations, bacteriological culture media each separately containing 0.05 percent, by

8 weight, of (2,4,5 trichlorophenoxy)diimidazol-1-ylphos phine sulfide gives percent kill and control of the respective culture, namely, Aspergillus-terreus, Pullulz'zria pullulans, and Rhizopus nigricans.

In further operations, (2,4-dichlorophenoxy)-isopr0pyl-. aminoimidazol-l-ylphosphine sulfide gives substantially complete controls and kills of bean mildew when appli ed to plants infested with the causative agent thereof in a composition as the sole toxicant at a concentration of parts per million parts, by weight; i The starting compounds represented by the formula \u P-Cl are known compounds and can be prepared by reacting compound of the formula I G-H and a compoundof the formula preferably in an inert organic solvent andin the presenceof a hydrogen halide acceptor at a temperatureo'f from 35 to 80 C. Y t

The starting compounds represented by the formula" are also known compounds. They are prepared by reacting the phosphite of the formula 1 v it GPClz compounds.

What is claimed is: 1. The compound corresponding to the formula Rlln wherein X and X represent oxygen orsulfur; R represents: hydrogen or loweralkyl of from 1 to 4 carbon atoms; R represents bromo, chloro, cyano, nitro or loweralkoxy of from 1 to 4 carbon atoms; R" represents'brorno, chloro or loweralkyl of from 1 to 4 carbon atoms withn.

representing the integer 0, 1 or 2; and G represents "N- loweralkylamino or N,N-diloweralkylamino of 1. to 4 car:

bon atoms.

2. The compound of claim -1 which-is (2 chloro-4fti. butyl-phenoxy) diethylaminoimidazol-l -ylphosphineoxide 3. The compound of claim 1 which is (2-'chloro-.4-t l butyl-phenoxy)dimethylaminoimidazol l=ylphosphine sul-;

butyl-phenoxy) isopropylamine (2 phosphine sulfide.

together substantially equir'nolecular; pro oiu nspr' 4. The compound of claim-1 whichis (2-chloro-4-tmethylimidazol-l-vn- 5. The compound of claim 1 which is (2-ch1oro-4-tbutyl-phenoxy)isopropylamino(Z-ethylimidazol 1 y1)- phosphine sulfide.

References Cited UNITED STATES PATENTS Cramer et aL: Chem. Ber., vol. 94, pp. 1612-21 (1961 German printed application 1,113,937 (1961).

5 HENRY R. JILES, Primary Examiner Mdtzer et a1 26O 309 N. TROUSOF, Assistant Examiner Koopmans et a1 260-309 Parts 2 0 309 US. Cl. X-R.

Nielsen et a1 260-309 10 260959, 960; 424-273 E22 3? 9 UNITED STATES PATENT omcn' CERTIFICATE OF CORRECTION Patent No 3,519,639 Dated Y July 1970 Inventor(s) Paul B. Budde and Henry Tolkmith It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 5 please insert the following after the last word in line 5 (solution) and before the first word in line 55 (is):

After the addition is complete the reaction mixture Signed and sealed this 27th day of April 1 971 SEAL) Attest:

EDWARD M.FLETCHER,JR WILLIAM E SCHUYL O A o o Attesting Officer Commissioner of Patents 

